Spinal cord infarction due to aortic dissection during coronary artery bypass grafting under percutaneous cardiopulmonary support

We report a case of aortic dissection due to improper position of a percutaneous cardiopulmonary support (PCPS) cannula into the femoral artery during coronary artery bypass grafting (CABG). A 77-year-old man with 3-vessel disease underwent off-pump CABG (OPCAB). Blood pressure suddenly lowered during bypass grafting to the right coronary artery. PCPS was performed between the left femoral artery and the right atrium. Bradycardia occurred 37 min after initiation of PCPS, and transesophageal echocardiography revealed Stanford type A aortic dissection. By converting the perfusion site from the femoral artery to the right axillar artery, the false lumen disappeared and did not reccur after cessation of PCPS. Therefore, the aorta was not replaced. He had however, bilateral leg paralysis after surgery. Magnetic resonance imaging (MRI) revealed spinal cord infarction caused by aortic dissection. Computed tomography (CT) confirmed disappearance of the false lumen and no expansion of the aorta 1 month after surgery. Meticulous care should be taken of the site and size of the arterial cannula in the extracorporeal circuit in such cases.     

Protection of visceral organs with an aortic occlusion balloon catheter and by femoral perfusion in aortic arch replacement

A 68-year-old man developed hemoptysis. Prominent left 1st arch was pointed out by chest X-p, and enhanced computed tomography (CT) revealed 60-mm distal arch aneurysm. Protrusion of the aneurysm strongly suggested aorto-pulmonary fistula. The operation was performed via median sternotomy. Cardiopulmonary bypass was established with the ascending aorta cannulation. During systemic cool down, an aortic occlusion balloon (Equalizer) was inserted in the right femoral artery and its position was monitored by transesophageal echography. Femoral perfusion cannula was inserted in the right femoral artery distal to the site of the Equalizer insertion. When the rectal temperature reached 28 degrees C, Equalizer was inflated and femoral perfusion was started. After the aortic arch was incised, balloon-tipped cannula were inserted into the aortic arch vessels. At this point, separate antegrade cerebral perfusion and lower body perfusion were established. The aortic arch was replaced with woven Dacron tube graft. It took 60 minutes to accomplish distal anastomosis, and urination was 80 ml during this period. Postoperative course was uneventful without renal dysfunction. This method of visceral organ protection seemed to be useful for the patients with impaired renal or liver function and for the patients whose distal anastomosis is difficult.     

Axillary Artery Perfusion in Acute Type A Aortic Dissection Repair

Abstract Background: We evaluated our experience with axillary artery perfusion technique in acute type A aortic dissection repair. Methods: Between September 2000 and July 2006, 41 consecutive patients with acute type A aortic dissection underwent surgical repair. In 35 of 41 patients (85.4%), arterial perfusion was performed through right axillary artery and in the remaining six patients (14.6%), arterial perfusion site was femoral artery. Indication for femoral artery perfusion was cardiac arrest and ongoing cardiopulmonary resuscitation in one and pulslessness of right upper limb in five patients. Mean age was 54.9 ± 15.3 (16 to 90 years) and 28 were male. Unilateral antegrade cerebral perfusion (perfusate temperature 22 to 25 °C) through axillary artery was performed in all axillary artery perfused patients and in three patients who had femoral artery perfusion. Results: Five patients died postoperatively (hospital mortality 12.2%). All of them had evidence of single or multiple organ malperfusion preoperatively. We did not experience any new transient or permanent neurologic deficit after the procedure in the unilateral antegrade cerebral perfusion patients. Complications related to axillary artery cannulation were observed in two patients (5.3%). One patient with femoral artery cannulation experienced femoral arterial thrombosis, postoperatively. Conclusions: Right axillary artery cannulation for repair of acute type A aortic dissection is a simple and safe procedure. In the case of pulslessness of right upper limb, femoral artery is still the choice of cannulation site.     

Axillary artery perfusion for the extensive arterial vascular disease]

Usefulness of axillar artery perfusion for the cases with severe systematic atherosclerosis was reported. It is generally accepted that the femoral artery is a common arterial cannulation site when performing the surgery of ascending aorta and total aortic arch. However, atheroembolism is one of the most severe complication for the patients with extensive arterial vascular disease by using femoral arterial perfusion. Axillar artery perfusion can prevent these complications, and the perfusion through the artificial graft anastomosed to the axillar artery can also avoid the malperfusion of the vertebral artery and axillar artery. We concluded that the axillar artery perfusion via artificial graft is useful alternative for aortic surgery.     

Simplified technique for aortic arch replacement. First-stage right subclavian-to-left carotid artery bypass

A simplified operative and perfusion technique for aortic arch replacement is described. Prior to definitive operation a right subclavian-to-left carotid artery bypass is performed using a Dacron graft. At the time of aortic arch replacement the right axillary artery is cannulated; this perfuses the right subclavian, right carotid, and left carotid arteries through the shunt, thus perfusing the entire brain. The rest of the body is perfused through a cannula in the femoral artery. This technique obviates the hazards and inconvenience of direct cannulation of the carotid arteries through the aneurysmal sac. The creation of such a shunt also reduces the time required for arch replacement, as the left carotid artery does not need a separate anastomosis.     

A femoral artery cannula that allows distal blood flow

OBJECTIVE: A femoral artery cannula is used for certain types of circulatory support but can cause ischemia, especially during prolonged perfusion. This study tests the function of a femoral cannula designed to allow proximal and distal blood flow. METHODS: Five pigs were used in the study. In each animal a distal-flow cannula was implanted in the femoral artery of one leg, and the same-sized standard cannula was implanted in the other. Blood was drained from the left atrium and delivered to the femoral artery through the distal-flow cannula or standard cannula by using a centrifugal pump. An ultrasonic flow probe and microspheres were used to quantify flow and perfusion distal to the cannula. RESULTS: Distal femoral flow and tissue perfusion were present in all animals (5/5) with the distal-flow cannula but only in 1 of 5 animals with the standard cannula (P < .048). Distal flow did not change with pump flow. Mean distal flow at each level of pump flow was higher with the distal-flow cannula (P < .05). Tissue perfusion was also higher with the distal-flow cannula (0.052 +/- 0.028 vs 0.010 +/- 0.022 mL x min(-1) x g(-1), P < .03). CONCLUSIONS: In the swine model the distal-flow cannula allowed greater and more consistent distal flow than the standard cannula. The use of a distal-flow cannula for circulatory support might reduce the risk of distal limb ischemia.     

Thoracic and thoracoabdominal aneurysm repair under deep hypothermia using subclavian arterial perfusion

BACKGROUND: Hypothermic circulatory arrest is a valuable adjunct for thoracic and thoracoabdominal aortic aneurysm repair. Retrograde aortic perfusion through the femoral artery, however, carries a risk of cerebral embolism or malperfusion. To avoid these complications we adopted antegrade aortic perfusion through a prosthetic graft attached to the left subclavian artery through a left thoracotomy. METHODS: Ten patients had repair of descending thoracic and thoracoabdominal aortic aneurysm under deep hypothermia with antegrade aortic perfusion through the left subclavian artery. Hypothermic circulatory arrest was used because proximal aortic control was hazardous due to rupture or intraluminal disease, or for spinal cord protection. RESULTS: There was no brain injury and one hospital death. The cause of death was massive bleeding from the gastrointestinal tract not related to deep hypothermia or the perfusion method. All 9 survivors were alive and well after a mean follow-up period of 9 months. CONCLUSIONS: Using the left subclavian artery as a site of aortic perfusion can avoid retrograde aortic perfusion, hence reducing the potential for brain injury due to embolic stroke or malperfusion through a dissected thoracoabdominal aorta.     

A comment on aortic perfusion cannulas.

An improved aortic perfusion cannula is described. The portion that passes through the aortic pursestring suture is tapered. The cannula can thus adapt to any enlargement of the cannulation site and miminize annoying leakage of blood during cardiopulmonary bypass.     

Arch and descending aortic aneurysms: influence of perfusion technique on neurological outcome.

OBJECTIVE: Although cannulation of the femoral artery is used routinely for thoracic aortic operations with hypothermic circulatory arrest, retrograde perfusion through the descending aorta carries the risk of cerebral malperfusion or embolism. We have, therefore, routinely used a central cannulation technique for distal arch and descending aortic operations since 1995. In this study, we compared neurological outcome in consecutive patients undergoing femoral versus ascending aortic perfusion for these aneurysms. METHODS: Between 1987 and 1998, 61 patients underwent aortic resection with circulatory arrest, but without retrograde cerebral perfusion, for lesions of the aortic arch and descending aorta. Thirty-one patients had fusiform true aneurysms, 19 had aortic dissection and 11 had extensive saccular or false aneurysms. Thirty-two patients (52%) were perfused via the femoral artery (group A), and 29 patients (48%) from the ascending aorta (group B). Operative mortality and morbidity, and neurological outcome, were reviewed. RESULTS: There were no differences between the groups in mean age, pathology, abdominal and peripheral vascular disease, net perfusion time, or circulatory arrest time. There were four hospital deaths (three in group A and one in group B; P = 0.61), including one neurological death in group A, group A suffered a higher incidence of neurological events (nine patients: 28%) than group B (two patients: 7%; P = 0.03). Temporary focal neurological deficits occurred in both groups (two patients in group A, 6% and two patients in group B, 7%; P > 0.99), but permanent injury occurred exclusively in group A (seven patients: four with monoplegia, one with hemiplegia, and two with diffuse cerebral injury with one death; P = 0.01). CONCLUSIONS: Anterograde perfusion using a proximal aortic cannula provides a low risk of cerebral embolism and allows extensive aortic resection with low morbidity.     

A successful repair of intraoperative retrograde type A aortic dissection in a patient with aortic regurgitation and ascending aortic aneurysm

The patient was a 67-year-old male with aortic regurgitation and ascending aortic aneurysm. We noticed the type A retrograde aortic dissection occurring from the cannulation site through the right femoral artery. We discontinued cardio-pulmonary bypass immediately, and established selective cerebral perfusion (SCP) eleven minutes after retrograde cerebral perfusion (RCP). We underwent simultaneous aortic valve replacement and ascending and arch graft replacement with an aid of SCP combined with RCP and systemic low flow perfusion. Postoperative course was satisfactory, although patient had a transient neurologic deficit. Intraoperative aortic dissection is a rare but potentially fatal complication. RCP may be a simple and useful method in emergency operation for intraoperative retrograde type A aortic dissection to avoid serious cerebral damage.     

Norwood operation without circulatory arrest: a new surgical technique

Circulatory arrest (CA) is associated with potential neurologic injury. We have developed a new surgical technique to eliminate CA during the Norwood operation. A modified Blalock-Taussig shunt (BTS) was fully constructed before cannulation for cardiopulmonary bypass. The aortic cannula was inserted in the patent ductus arteriosus to allow systemic cold perfusion. When deep hypothermia was reached, the aortic cannula was redirected into the pulmonary artery (PA) confluence. Both cerebral and systemic perfusion were maintained through the right PA and BTS into the innominate artery.     

Shaggy and calcified aorta: surgical implications

Atheroembolism is an emerging problem in cardiovascular surgery, especially in elderly patients. Severe atherosclerosis of the thoracic aorta usually reflects systemic atherosclerosis. Aggressive preoperative and intraoperative evaluation of the aorta using enhanced CT, transesophageal echocardiography and epiaortic ultrasound is important in elderly patients as well as those with systemic atherosclerosis. To prevent atheroembolism, it is important to select an adequate arterial perfusion site and to avoid touching the diseased aorta until circulatory arrest. In atherosclerotic aortic arch aneurysm, central cannulation under ultrasound guidance and directing the dispersive cannula toward the aortic root is a simple and effective perfusion strategy. Axillary perfusion is useful as an alternative to central cannulation in atherosclerotic aortic disease, but special care is necessary to avoid complications when the patient has a small axillary artery or flail atheroma around the arch vessels. In femoral artery perfusion, retrograde perfusion may induce paradoxical cerebral embolism, but the incidence of stroke is comparable with axillary perfusion when there is adequate preoperative screening using transesophageal echography. Circulatory arrest with/without cerebral perfusion is another important strategy when the aorta has severe atherosclerosis. Recent literature has shown that mild hypothermia may be safe for anterior cerebral perfusion during circulatory arrest, but optimal flow rates and time limitations are unknown. A simple calcified aorta called “porcelain aorta” may be managed by circulatory arrest, local debridement and the clamp method. Several surgical options are proposed for this clinical entity but their use will diminish in the future because of transcatheter valve replacement.     

A new technique for perfusion of the heart during aortic valvular surgery on a beating heart

A new technique of perfusion of the heart during aortic valvular and combined aortic valvular and coronary artery surgery on the beating heart is presented. The inflow for perfusion is via a dual system: the coronary sinus is perfused with blood from a calibrated centrifugal pump connected to the oxygenator; the coronary ostia are perfused with blood from the ascending aortic cannula. The advantages of this new technique of perfusion of the heart are discussed. A new technique of perfusion of the heart during aortic valve surgery is presented, utilizing a dual system: one utilizing a pump, the other derived from the aortic cannula.     

Successful complete repair of interrupted aortic arch and associated with DiGeorge syndrome in neonate]

We report a rare case of interrupted aortic arch and a right aortic arch associated with DiGeorge syndrome, in neonate. Through a median sternotomy bypass was established placing an arterial perfusion cannula both in the ascending aorta, and in the main pulmonary artery. The right and left pulmonary arteries were temporarily occluded, while this pulmonary cannula perfused the lower part of the body. The arch reconstruction was performed during profound hypothermic total circulatory arrest. The right descending aorta had an adequate length and direct anastomosis was carried out without any tension. The VSD was repaired through a right atrial approach. The patient had hypocalcemia and thymic abnormalities which was consistent with the DiGeorge syndrome. He was treated with calcium gluconate and alfacalcidol, but no serious infection due to immunodeficiency was seen after operation. Post operative catheterization revealed no pressure gradient at the site anastomosis of the aortic arch and satisfactory results.     

Cannulation of the axillary artery for cardiopulmonary bypass: safeguards and pitfalls

BACKGROUND: The ascending aorta is the customary site for arterial cannulation for cardiopulmonary bypass. Favorable experience at our institution and elsewhere using axillary artery cannulation in treating type A aortic dissections has caused us to broaden our indications for using this site for arterial cannulation for cardiopulmonary bypass. METHODS: Medical records, operative notes, and perfusion records were reviewed in all patients in whom the axillary artery was cannulated directly or by a graft for cardiopulmonary bypass from January 1, 2000 through August 30, 2002. RESULTS: Seventy-five patients underwent axillary artery cannulation during the 32-month interval. Eleven patients had ascending aortic dissections, 20 had extensively diseased ascending aortas, and 44 were individuals undergoing repeat cardiac procedures. The right axillary artery was used in 72 patients and the left in 3. In 16 patients the artery was cannulated directly, and in 59 the arterial cannula was inserted into a prosthetic graft that had been anastomosed to the axillary artery. Axillary artery cannulation was satisfactory in 95% (71 of 75) of the cases in which it was used. CONCLUSIONS: Cannulation of the axillary artery for cardiopulmonary bypass is a dependable approach for procedures including reoperations, aortic dissections, and extensively diseased ascending aortas.     

Hypothermic circulatory arrest through a left thoracotomy in a 12-year-old child with aortic coarctation

Surgical correction of adult complex aortic coarctation using hypothermic circulatory arrest often requires central cannulation to secure cerebral perfusion. It is not easy to place the cannula in the ascending aorta, however, especially in children undergoing surgery through a left thoracotomy. In a 12-year-old male with hypoplastic distal aortic arch, we placed an arterial cannula in the ascending aorta using the Seldinger puncture technique through the stenotic segment of the distal aortic arch. Replacement of the stenotic segment with a 20 mm-size Dacron graft was then routine. The ascending aorta was exposed only for the proximal anastomosis. The left subclavian artery was also reconstructed. This central cannulation technique is simple and is useful in repairing complex aortic coarctation.     

Surgery for thoracic aortic aneurysms involving the distal arch through a left thoracotomy

Surgical outcome for thoracic aortic aneurysms involving the distal arch via a left thoracotomy using retrograde cerebral perfusion combined with profound hypothermic circulatory arrest was reviewed. Twelve patients with a atherosclerotic aortic aneurysm between 1994 and 1997 were involved. A proximal aortic anastomosis was made by means of an open aortic technique. For the first four patients, oxygenated arterial blood from cardiopulmonary bypass was perfused retrogradely through a venous cannula positioned into the right atrium. In the last eight cases, venous blood provided by a low-flow perfusion of the lower half body via the femoral artery, which was still oxygen-saturated, was circulated passively in the brain in a retrograde fashion with the descending aorta clamped. Prosthetic replacement was done between the distal arch and the proximal descending aorta in 6 patients and from the distal arch to the entire descending thoracic aorta in 6 patients. The median duration of hypothermic circulatory arrest and continuous retrograde cerebral perfusion was 36 minutes and 33 minutes respectively. The overall outcome was satisfactory without early mortality--all patients survived, although an octogenarian died of respiratory failure 1 year postoperatively. Another octogenarian with a ruptured aneurysm developed delay of meaningful consciousness, and other two patients with a severely atherosclerotic aneurysm suffered permanent neurological dysfunction (stroke) presumably due to an embolic episode. The safe and simple combination of profound hypothermic circulatory arrest, retrograde cerebral perfusion, and open aortic anastomosis protects the brain adequately and produces satisfactory results in surgery for aortic aneurysms involving the distal arch through a left thoracotomy.     

Bronchial artery perfusion during cardiopulmonary bypass does not prevent ischemia of the lung in piglets: assessment of bronchial artery blood flow with fluorescent microspheres.

OBJECTIVE: Blood supply of the lungs during total cardiopulmonary bypass (CPB) is limited to flow through the bronchial arteries. This study was undertaken to assess the bronchial artery blood flow during CPB with fluorescent microspheres in a piglet model. METHODS: We subjected ten piglets (mean weight 5.0+/-0.5 kg) to 120 min of normothermic, total CPB without aortic cross-clamping, followed by 60 min of post-bypass perfusion. Fluorescent microspheres were injected into the left atrium or the aortic cannula or distal to the cannula to assess bronchial artery blood flow before, during and after CPB. The reference samples were taken from the descending aorta. We compared the different sites of injection. Tissue samples of the lungs were taken before and 60 min after CPB. RESULTS: Before CPB, total bronchial artery perfusion was 43.6+/-14.1 ml/min (4.8+/-1.3% of cardiac output) as by injection distal to the aortic cannula. These values were not different when microspheres were injected into the left atrium or the aortic cannula. There was no difference in scatter or in the amount of microspheres in the reference samples among the three injections sites. During CPB, bronchial artery perfusion was significantly decreased (4.4+/-2.4 ml/min vs. 40.0+/-5.0 ml/min before CPB) and returned to baseline values 60 min after CPB. Light microscopy of the tissue samples revealed alveolar septal thickening and a decrease in alveolar surface area after 60 min of reperfusion which was associated with a decreased capacity to oxygenate blood. CONCLUSIONS: (1) Bronchial artery blood flow can quantitatively be assessed during CPB when microspheres are injected into the ascending aorta and the reference samples are taken from the descending aorta. (2) Despite adequate perfusion pressure bronchial artery blood flow is decreased substantially during CPB. (3) The decrease in blood flow and the ultrastructural changes present at the end of CPB suggest the presence of low-flow ischemia of the lung during total CPB.     

Femoral cannulation is safe for type A dissection repair

Background

Recently, surgeons have embraced axillary artery cannulation for type A aortic dissection repair out of concern for malperfusion phenomena with traditional femoral artery cannulation. My colleagues and I sought to determine whether these concerns are justified.

Methods

Records of 86 consecutive patients (51 men and 35 women; age, 30 to 86 years; mean, 62 years) undergoing surgical repair for acute type A dissection were reviewed. Cannulation site, specific operative repair, and complications related to cannulation were noted.

Results

Seventy-nine cannulations were performed in the femoral artery (47 left, 23 right, and 9 unspecified), 3 in the axillary artery (1 left and 2 right), and 4 in the ascending aorta or arch. Deep hypothermic arrest was used in 64 operations. Seven involved re-sternotomy. Seventy patients had supracoronary grafts (2 with valve replacement and 10 with valve resuspension), and 16 underwent aortic root replacement. Fourteen patients were in shock from cardiac tamponade. Eighty patients survived the operation, and 71 were hospital survivors. Malperfusion on initiation of cardiopulmonary bypass was noted in 3 patients. In 1, the original cannulation site was the ascending aorta, and the cannula was moved to the femoral artery for correction. In 2, the original cannulation site was the femoral artery, and the cannula was moved to the ascending aorta. Malperfusion on clamping of the aorta or on resumption of aortic flow was noted in no patient. Postoperative ischemia of any vascular bed was noted locally only in 3 (cannulated) lower extremities.

Conclusions

Straight femoral cannulation for all phases of type A dissection repair is appropriate and yields excellent clinical results. The anticipated malperfusion events are actually rare (2 of 79 with femoral artery cannulation, or 2.5%).     

Repair of acute ascending aorta-arch dissection with continuous body perfusion: a case report

An approach for the replacement of the distal ascending aorta-proximal arch and acute dissection is described. During the operation, the patient's entire body was continuously perfused, the aortic arch was excluded from the arterial circulation, and the aorta was not clamped at any time. To achieve continuous body perfusion, we independently cannulated the right axillary and the left femoral arteries. The right atrium was cannulated for systemic venous return, and the right radial artery was used for arterial blood pressure monitoring. The myocardium was protected with retrograde cardioplegia, and the body was protected with moderate hypothermia. Vascular clamps were placed to the proximal innominate, left carotid, and left subclavian arteries without discontinuing perfusion of the right axillary artery. A temporary clamp was applied to the femoral line, the aorta was transected, and a large Foley catheter was inserted through the true aortic lumen. The Foley bulb was positioned in the proximal descending thoracic aorta and distended with saline until the aortic blood return ceased. The femoral line clamp was removed from the cannula, and the entire body was perfused during the completion of the distal aortic anastomosis. At the completion of the anastomosis, the Foley bulb was slightly deflated. Once the inserted graft was filled with blood, a large vascular clamp was applied to the graft, and the previously placed clamps were removed from the arch branches. The femoral line was removed, and the body was perfused and rewarmed via the axillary cannulation. Following completion of the proximal graft-aortic anastomosis, the heart was reperfused, and all cannulas were removed in the usual fashion. Rapid recovery characterized the patient's initial postoperative course; however, multiple organ failure secondary to pump-induced inflammatory response followed. Aggressive medical management resulted in complete patient recovery. No neurologic deficits were observed, and the patient regained full cognitive function. This report describes a simple approach to facilitate repair of the aortic arch and minimize postoperative organ failure.